Malaria continues to kill over a million people each year and in many populations affected by malaria, conventional drugs are often unaffordable or inaccessible. Historically, plants have been a prominent source of antimalarial drugs. Those plants currently used by indigenous people to treat malaria should be documented and investigated as potential sources of new antimalarial drugs.

Aim of the study:
To investigate in vivoantimalarial activity, toxicity and carry out phytochemical
screening of selected plants which have been used in traditional medicine for the treatment of malaria.

Materials and methods:
Organic and water extracts of four medicinal plants used for the treatment of
malaria in traditional health systems of Msambweni people in Kenya were tested for antimalarial activity against Plasmodium berghei and brine shrimp lethality. They were also screened for their major phytochemical constituents.

Results:
Aqueous extract of the stem bark of Adansonia digitata exhibited highest chemosuppression of parasitaemia, > 60% in a murine model of Plasmodium berghei infected mice. Aqueous and organic extracts of
Launaea cornuta and Zanthoxylum chalybeum were toxic to the brine shrimp (LD 50 o 1000 mg/ml) while aqueous and organic extracts of Adansonia digitata and aqueous extracts of Canthium glaucum were not toxic to brine shrimp (LD50 > 1000mg/ml). Phytochemical screening revealed the
presence of alkaloids and flavonoids in all the crude extracts of the selected plant species studied. Sesquiterpene lactones and saponis were present in organic extracts but absent in the aqueous extracts of Adansonia digitata,
Canthium glaucum, Launaea cornuta and Zanthoxylum chalybeum.
Conclusion:

The results showed that the crude extracts of Adansonia digitata and Canthium glaucum demonstrated promising antimalarial activity and there is potential for isolation of lead compounds from their extracts.

Infectious diseases are prevalent and life threatening in Kenya. Majority of the sick are seeking herbal remedies in search of effective, safe, and affordable cure. This project aims to investigate the antimicrobial activity and presence of active phytochemical compounds in different parts of Vernonia glabra ; a plant used by herbalists in various regions of Kenya, for the treatment of gastrointestinal problems. The plant sample was collected in January 2010 in Machakos, and different parts dried at room temperature under shade, ground into powder and extracted in Dichloromethane: Methanol in the ratio 1:1, and water. These crude extracts were tested against Staphylococcus aureus, Escherichia coli, Candida albicans, and Aspergillus niger for antimicrobial activity using disc diffusion technique. Minimum inhibitory concentrations (MICs) for active crude extracts were done using disc diffusion technique after the failure of agar and broth dilution methods. It was observed that the organic crude extracts of flower, leaf, stem, root, and/or entire plant, showed activity against one or four micro-organisms, and at concentrations lower than the aqueous crude extracts. Organic crude extract of the leaf showed the highest activity against Staphylococcus aureus (mean inhibition zone 1.85), recording higher activity than the commercially used standard antibiotic (Streptomycin mean inhibition zone of 1.30). The organic crude extract of flower showed significant activity only against S.aureus , with the lowest MIC of 1.5625mg/100μl, compared to streptomycin with M.I.C of 6.25mg/100μl. Thin Layer Chromatography-Bioautography Agar-Overlay showed that, flower alkaloids (50% active), root sapogenins (43.8% active), and root terpenoids (38.5% active) were identified as the potential antibacterial compounds against S.aureus. These results suggest that, V.glabra contains phytochemicals of medicinal properties and justify the use of V.glabra in traditional herbal medicine for the treatment of microbial based diseases. However, research on toxicity which is missing in this study is recommended for V. glabra in order to verify, validate and document the safety of this medicinal plant to the society.

Abstract
Herbal drugs have been used since ancient times as medicines for the treatment of a wide range of diseases, for both human and livestock. A study conducted in the Lake Victoria Basin Kenya revealed vast knowledge and reliance on traditional medicine as source of healthcare. The study documented 34 medicinal plant species distributed among 21 botanical families and 34 genera, used in the management of human ailments. The highest numbers of species were from the families Asteraceae and Leguminosae. The most commonly harvested plant parts were leaves (46.51%) and roots (34.88%). The most common growth forms utilised were herbs (40.54%) followed by shrubs (27.03%). The major methods of herbal drug preparation were concoction (31.03%) and decoction (24.14%) administered mainly through oral and dermal routes, (64.29%) and (32.14%) respectively. The use of herbal drugs as mixtures was reported to be a common practice by the herbal practitioners; 57.14% of the preparations were dispensed as mixtures while 42.86% of the preparations composed single plants. A rich knowledge of medicinal plants was recognized and phytochemical and bioactivity analyses of these herbal plants are recommended to determine their safety and efficacy.

Alkaloids, saponins, anthraquinones, glycosides, phenolics, terpenoids and flavonoids distribution in ten medicinal plants belonging to different families were assessed and compared. The medicinal plants investigated were Asparagus racemosus, Clutia abbysinica, Clerodendrum myricoides, Ehretia cymosia, Leucas calostachys, Toddalia asiatica, Rubia cordifolia, Spermacoce princeae,Carrisa edulis
and Ajuga remota. The leaves and roots of the plants were collected from their natural habitat
in Aldai division South Nandi district. All the plant samples were identified at University of Nairobi and confirmed in National Museums of Kenya. The Voucher specimens were deposited in the University Botanic Garden Maseno herbarium. The harvested roots were washed with water and the barks peeled off while still fresh and cut into small portions. The materials were then air –dried under a tree shade at room temperature for one week when possible, but in the sun whenthe humidity was too high. Phytochemical screening was carried out at Centre for Traditional Medicine and Drug Research (CTMDR) KEMRI Nairobi according to Harborne, (1984 & 1973. All plants were found to contain alkaloids, terpernoids , saponins and flavonoids except for the absence of saponins in root extracts of
R. cordifolia and C.myricoides and flavonoids in leave extracts of L. calostachys and A. remota.
The significance of the plants in traditional medicine and the importance of the distribution of these constituents were discussed with respect to the role of these plants in ethnomedicine in South Nandi District.

ABSTRACT
Use of herbs as combinations is a common practice with many herbal practitioners. The main idea behind this usually is the synergistic action expected to take place by the traditional healer hence being able to give better results as compared to one herb and also treat more than one ailment, even those not mentioned by the patient. However, other interactions such as additive and antagonism too take place when herbs are used in combinations. In this study, anti-aspergillus and anti-candida efficacy of crude extracts of five plants used in combination to treat malaria were investigated. Toddalia asiatica (root), Rhamnus staddo (root) , Momordica foetida (shoot), Podocarpus falcatus (bark), Aloe sp (secculent leaves) used by traditional health practitioners in the Kalenjin community were extracted using water and dichloromethane/methanol (1:1) and the crude extracts tested for in vitro antifungal activity singly and in combinations against Aspergillus niger and Candida albicans. Dichloromethane/methanol extracts of P. falcatus showed the highest activity (77.77% inhibition) against A.niger while M. foetida showed the highest activity (77.78% inhibition) against C. albicans. Aloe sp. Showed no activity against A. niger when tested singly. A.niger was more sensitive to the plants extracts than C.albicans. Aqueous extracts did not show any activity. Antagonism, additive and synergism were observed when combinations of the herbal plants were assayed. Findings in this study are a preliminary verification of the usefulness of using herbal plants in combinations as a prevalent practice among the traditional healers.

Traditional medicine has utilized plants to palliate, cure and/or prevent diseases in both humans and animals. The acquisition of knowledge has been through trial and error, and observation. Today, the enhanced search for botanical drugs throughout the world has increased the need for accurate means of identifying plants with possible pharmacological and biological activity. A number of methodologies have been used in selecting plants likely to possess pharmacological properties, but many have recorded low success rates. Data reported in this paper reveal that the accuracy of identification of these herbal drugs for pertinent ailments using ethnobotanical data is almost as accurate as techniques applied in modern medical practice. This paper discusses the value of ethno-botanical data in the preliminary search for potential drug plants Key words: Ocimum, Plectranthus, ethnobotany, medicinal plants.

Abstract

Ethnopharmacological relevance

The study of local knowledge about natural resources is becoming increasingly important in defining strategies and actions for conservation or recuperation of residual forests.

Aims of the study

This study therefore sought to collect information from local populations concerning the use of Nandi Forest medicinal plants; verify the sources of medicinal plants used and determine the relative importance of the species surveyed.

Materials and methods

Data was obtained using semi-structured forms to record the interviewee's personal information and topics related to the medicinal use of specific plants. A total of 40 medicinal plants used locally for the treatment and/or control of human ailments were collected through interviews conducted with selected traditional doctors and professional healers.

Results

This study demonstrated that local people tend to agree with each other in terms of the plants use and that leaf material form the major component of plant parts exploited. The other harvested materials consist of stem bark, the roots and the whole plant, though at a lower intensity for making liquid concoctions from different plants. Majority of the remedies were prepared from a single species. In most cases, the mode of administration was oral. In the forest, some of the plants collected were scarce. This scarcity was attributed to indiscriminate logging, overexploitation, poor harvesting methods and current agricultural trends.

Conclusion

Conservation procedures and creation of awareness were identified as the main remedies to the current situation.

Vegetative propagation studies were carried out at Maseno University, Kenya in the year 2004 and 2005 using stem cuttings on three endangered indigenous tree species namely Asystasia schimperi, Carissa edulis and Toddalia asiatica to test the effect of IBA on rooting of the stem cuttings of these plant species. Juvenile stem cuttings of these plant species were dipped in different concentrations of auxin (indole Butyric Acid (IBA) of 0, 100 ppm, 200ppm, 400ppm and 500ppm. Completely, randomized design (C.R.D) was used and the treatments replicated three times in a non mist polypropagator. The treated cuttings were planted in polythene pots. The duration of the experiment was four months. Data taken were plant height, number of leaves and number of rooted cuttings every 2 weeks. Data was subjected to analysis of variance (ANOVA) and means separated by L.S.D at 5% significance level. The results showed that hormone concentration, species and date of sampling affected the number of rooted plants, plant height and number of leaves Asystasia schimperi had the best rooting and subsequent plant growth followed by Carissa edulis and lastly Toddalia asiatica, .
It can be concluded that Asystasia schimperi and Toddalia asiatica can be propagated by stem cuttings easily hence farmers can cultivate them.

Plectranthus is a large and widespread genus with a diversity of ethnobotanical uses. The genus is plagued with numerous nomenclatural disharmonies that make it difficult to collate accurate data on the uses. The aim of this review is to gather together all ethnobotanical information on Plectranthus and to map the data onto the most up-to-date phylogenetic classification in order to see if there are similar uses among related species and hence provide a framework for the prediction and exploration of new uses of species. The uses of 62 species of Plectranthus were mapped onto a current phylogeny based on DNA sequence data. The phylogeny reveals two major Clades, 1 and 2. The members of Clade 1 (corresponding to the formally recognized genus Coleus ) were richer in number and diversity of uses than members of Clade 2 (comprising the remaining species of Plectranthus). The high incidence of synonymy can lead to problems in uncovering a species’ ethnobotanical profile. About 30% of all citations of Plectranthus use a synonym and most of the synonyms are attributed to 10 of the most used species, 9 of which are in Clade 1. Members of the ‘Coleus’ Clade are the most studied group both taxonomically and economically. The higher incidence of study may be as a result of the higher diversity of uses and the fact that species in Clade 1, such as Plectranthus barbatus, Plectranthus amboinicus andPlectranthus mollis, are geographically more widespread than those in Clade 2. Plectranthus species in Clade 1 are frequently used as medicines and are used to treat a range of ailments, particularly digestive, skin, infective and respiratory problems. Plectranthus used as foods, flavours, fodder and materials are also mostly found in Clade 1. Monoterpenoids, sesquiterpenoids, diterpenoids and phenolics have been reported in species of Plectranthus. The abietane diterpenoids are the most diverse of the diterpenoids isolated from species of Plectranthus. The labdane diterpenoid, forskolin, occurs in Plectranthus barbatus and could explain some of the traditional uses of this species. This review highlights the fact that not enough is known about the chemistry of other species of Plectranthus to explain their traditional uses.

Ocimum L. and Plectranthus L'Hér. are cosmopolitan genera in the tribe Nepeteoideae in the family Labiatae Juss. The accumulation of essential oils in their flower and foliage has contributed to their prominence and popularity in traditional and conventional medicine, in cosmetology and perfumery, in the food industry as preservatives and spices, and more recently in the manufacturing industry as ingredients for pesticides, plastics, paints, etc.

The taxonomic aspect of the group has lagged well behind the economic one. The latest world- wide account of the two genera was by Briquet (1895-7), more than 100 years ago. In both these taxa, the taxonomic delimitation has been inadequate, the major problem being the continuous nature of the variation of characters particularly the morphological ones, which results in difficulties in circumscription of species. To further complicate the situation, Ocimum species tend to hybridize readily and undergo polymorphism. Morphological characters have proved to be inadequate in delimitation of the genera. It is therefore imminent that other criteria be investigated to substitute or corroborate the morphological ones in the delimitation of these two genera.
The major aim of this project was therefore to find novel morphological characters or novel combinations of already known characters and the value of new criteria from phytochemical data and anatomy to augment the morphological data in the delimitation of Ocimum and Plectranthus. Field and herbarium collections were used in this study. Gas-liquid chromatography/mass spectrometry (GLC/MS) on the essential oils from field samples were conducted in the chemotaxonomic study while the surface anatomical characters of Plectranthus were analyzed using the scanning electron microscope (SEM). In the revision of Ocimum, new morphological characters have been identified that can differentiate between sections and even between species, for instance, in the dendrite-haired species of subsection Gratissima, O. cufodontii and O. jamesii have n-shaped while O. spicatum have bowl-shaped anthers. Morphological features separating O. basilicum and O. americanum were established. In Plectranthus, three new species namely, P. agnewii C. Lukhoba & A. Paton, P. xylopodus C. Lukhoba & A. Paton sp. nov. and P. kwalensis C. Lukhoba & J. Kokwaro as well as the varieties P. barbatus var. glabricalyx C. Lukhoba & J. Kokwaro and P. edulis var. longiflora C. Lukhoba & J. Kokwaro have been described. One name change, P. igniarius var. verdcourtii C. Lukhoba & J. Kokwaro formerly P. igniarius var. grandicalyx) has been made. The chemical analysis conducted on four Ocimum and eleven Plectranthus species revealed the presence of numerous essential oil constituents. Some compounds were species-specific, some genera-specific while others were common to both genera thus can be of taxonomic value. The species O. basilicum, O. kilimandscharicum and O. kenyense clustered together in the cluster analysis. These three species have traditionally been grouped together in the section Ocimum. O. gratissimum showed greater affinity to Plectranthus than to Ocimum. The Plectranthus species came out as one homogenous group with two subgroups. The anatomical analysis of Plectranthus showed the indumentum to have a large number of sessile glands (peltate, gland dots), some capitate glands and numerous multi-cellular eglandular hairs. The viscid species P. kamerunensis and P. agnewii had the highest number of capitate glands. The presence, structure and nature of the stomata and glands were of taxonomic importance. Seven species had amphistomatic stomata and another seven species had stomata on the stems. The stratification of the leaf and stem surfaces was also found to be taxonomically significant. Cluster analysis showed that members of subgenus Calceolanthus clustered together into one group. They were also distinct from subgenus Plectranthus. A key based on these anatomical characters was drawn up to identify species in Plectranthus. Ethnomedicinal data revealed that Ocimum and Plectranthus species are popularly used to cure or alleviate gastro-intestinal, febrile, respiratory and skin conditions. Four species namely, O. basilicum, O. kilimandscharicum, O. gratissimum and P. barbatus showed high potential for further pharmacological evaluation, and for incorporation into local health care systems. This data also revealed that the medicinal species in the two genera are greatly affected by the current degradation of the environment. Thus propagation of the potentially medicinal ones was recommended. It is recommended that future taxonomic revisions of the two genera should include chemotaxonomic and anatomical data as they have proved to be promising criteria. Members of the two genera that have substantial amounts of essential oils can be commercially utilized in industry. The promising medicinal Ocimum and Plectranthus species can be incorporated into the primary health care systems. It is hoped that the new criteria used in this study will be relevant for the on-going revision of the family Labiatae for the Flora of Tropical East Africa.

Traditional medicine has utilized plants to palliate, cure and/or prevent diseases in both humans and
animals. The acquisition of knowledge has been through trial and error, and observation. Today, the enhanced search for botanical drugs throughout the world has increased the need for accurate means of identifying plants with possible pharmacological and biological activity. A number of methodologies have been used in selecting plants likely to possess pharmacological properties, but many have recorded low success rates. Data reported in this paper reveal that the accuracy of identification of these herbal drugs for pertinent ailments using ethnobotanical data is almost as accurate as techniques applied in modern medical practice. This paper discusses the value of ethno - botanical data in the preliminary search for potential drug plants.

ABSTRACT The family Labiatae, commonly called the mint family, is one of the flowering group of plants that has been found to have great medicinal potential. In this study, at least twenty-eight (28) indigenous species which are popular among Kenyan herbalists have been collected from the Rift Valley and central parts of Kenya. Preliminary chemical analysis of the Ocimum genus has revealed several different components of essential oils. There is evidence that further and more intensive research on the medicinal aspects of the family is called for.